Effect of dietary supplementation of periphyton on growth performance and digestive enzyme activities in Penaeus monodon

A 60-day indoor growth trial was conducted to study the effect of dietary supplementation of periphyton on growth performance and digestive enzyme activities in Penaeus monodon juvenile. Periphyton developed over bamboo substrate in outdoor cistern tanks (15 m2) was used as a dietary supplement in P. monodon (2.02 ± 0.04 g) reared in 1000 l fiberglass reinforced plastic tank. Graded level of dried periphyton was included in shrimp basal diets; 0% (control), 3% (T1), 6% (T2), 9% (T3) and a control diet with natural bamboo substrate for periphyton growth (T4) served as a positive control. Significantly lower (p < 0.01) level of NO3-N, and PO4-P were noticed in T4 compared to other experimental groups, while no significant difference in other water quality parameters were noticed among the treatments. At the end of the feeding trial, significantly higher (p < 0.01) body weight was noticed in T2 (5.50 ± 0.21 g) and T4 (5.33 ± 0.13 g) compared with control (4.44 ± 0.17 g). Similarly, significantly better (p < 0.01) feed conversion ratio (FCR), 2.01 ± 0.08 and protein efficiency ratio (PER), 2.70 ± 0.12 was noticed in T2 compared to control (FCR 2.81 ± 0.19 and PER 1.94 ± 0.14) and T3 (FCR 3.58 ± 0.14 and PER 1.51 ± 0.06), while no significant difference was noticed between T4 and T1. At the end of the feeding trial, there was 75.45, 128.3, 178.5 and 76.6% significant increase (p < 0.05) in gut digestive enzymes amylase, cellulase, protease and trypsin respectively in T2 compared with control. Similarly, most of the digestive enzyme activities in T1 and T4 were superior compared to control and T3. However, treatment with 9% level of periphyton inclusion (T3) did not differ significantly (p > 0.05) for most of the digestive enzyme activities, growth, FCR and PER compared with control indicating inherent upper limit of periphyton inclusion. The present study elucidates the suitability of periphyton as a novel dietary supplement and its supplementation up to 6% in shrimp for enhancing growth and digestive enzyme activities in tiger shrimp juvenile.

► Suitability of periphyton as dietary supplement over conventional in situ periphyton and control
► Periphyton supplementation enhanced growth and digestive enzyme activity in P. monodon.
► Supplementation at 6% level performed better compared to shrimp grazed over bamboo substrate.
► Periphyton supplementation at 9% level did not differ with control.